The present invention relates to the field of metrology and more precisely the analysis and the characterisation of the consumption of any fluid flowing in a pipe. The fluid selected for illustrating an exemplary implementation of the invention is water or a liquid.
In order to best measure and manage the water consumption of a residential or industrial building, or an agricultural or industrial distribution network, it is necessary to know the specific consumption of the devices supplied by the network. The most obvious solution consists in associating with each device an individual meter the data of which make it possible to obtain a dynamic map and to act according to the individual data provided by these meters.
Solutions for the global analysis of the water consumption are also known in the state of the art.
The American patent application US20040128034 describes a solution for analyzing a liquid flow using a microphone or another acoustic sensor to detect the acoustic signature of the liquid flow through a pipe through the analysis of the acoustic signature of water or a liquid flowing through a pipe.
Based on the analysis of the acoustic signature of the liquid flow, a determination is made whether a leak in the line has occurred.
If a determination is made that a fault has occurred, a water shut-off valve is activated ceasing the flow of water or other liquid. The system further includes audible and visual warning devices to indicate whether a fault has occurred as well as the general system status. The system is configured to control the water mains leading into a building or it is configured to control the water leading into a specific hose or appliance such as a toilet or washing machine. The whole building system uses a computer to analyze the acoustic signatures detectable in the house and can determine if one of these signatures has been occurring for a time period outside an acceptable limit and determining that a fault has occurred.
The American patent application US2012/0116693 is also known, which describes a method for measuring the total water consumption in a multi-unit building.
Each unit comprises several water usage appliances. A sensor may be placed on the appliances. The sensor can be an acoustic sensor, e.g. a microphone. The sensor can detect the opening and the closing of the water usage or the water usage level.
The correlation between the consumption of water and the acoustic pressure and/or the spectral distribution of the sound of the water pipe of the unit and/or the appliance can be calibrated for each appliance. A processor unit receives via a wired or wireless network the total usage measurement and the monitoring data and correlates them to generate correlated data to produce data for the measuring of the individual consumption as compared to periods of water consumption. The processor unit is integrated in the meter of the main supply pipe or is positioned outside the building.
The American patent application US2006/0009928 describes the application of specific consumption signatures for characterising devices or detecting anomalies in such devices, used to improve the efficiency of water use. The measured data of the water flow during the use of the devices are transmitted to a microprocessor which is an integral part of a PC or a separate microprocessor, comprising means for informing a water flow controller.
The American patent U.S. Pat. No. 5,040,409 discloses the use of an acoustic sensor for detecting leaks in a sprinkler system. The sensor detects the signals having a different frequency generated by the normal flow or by the leakage of fluid in the pipes.
The American patent U.S. Pat. No. 3,500,676 discloses a method and a device for detecting leaks having a different sound frequency using a transducer comprising a component of the accelerometer type consisting of piezoelectric discs.
The American patent application U.S. 2003/0052790 discloses a system and method for communicating information between a water-meter and a personal computer or an external company.
The European patent EP1887327 discloses an ultrasonic meter comprising a water flow pipe, a piezoelectric sensor, a processor, a memory and an interface for connection to an external device.
The international application PCT WO2011/049957 describes the design of a data transmitter receiver device for a water-meter of the AMR or AMI type having a memory card as a program storage device and an external device with a USB port as an interface.
The solutions of the prior art have several drawbacks.
First, they all require the positioning of an additional device inside the water supply circuit. This implies the shut-off of the water supply, a major action on the pipe or the distribution circuit, and the at least temporary disruption of the network.
Secondly, the solutions of the prior art do not actually provide information individually characterising the water consuming devices, but rather information about the consumption of a sub-set, such as a bathroom or a kitchen.
Solutions belonging to the technological background are also known in the prior art:
The American patent U.S. Pat. No. 6,161,100 describes a system wherein each water-using device is equipped with an individual meter. This is precisely the solution that the invention seeks to avoid.
The international patent application WO2006/110600 provides a device (fixture) provided with an individual sensor.
The European patent EP036658 also describes an ultrasonic flow meter. This sensor comprises two ultrasonic transducers:                the first one emits a wave front in a direction determined relative to the flow flowing in the pipe; and        the second one detects the wave scattered after the interaction between the aforesaid wave front and the fluid flowing in the pipe to provide a signal representative of the speed of the fluid in the pipe.        
This solution of the prior art teaches neither the object of a single consumption sensor for characterising the consumption of a plurality of water-consuming devices, nor the mode of acquisition of the signals, enabling the characterisation of the specific consumption from a unique item of information.
The Japanese patent application JP 2006-047243 falls within the same technical field as the previous document, namely ultrasonic flow meters and not the characterisation of a plurality of devices through the analysis of the signals using an electromechanical sensor.
It specifies a solution using a clamp easily movable on pipes for enabling quick measurements on an installation.
The European patent GB2082324A discloses a device for monitoring the operation of a fluid flow system comprising a microphone intended to be attached to a pipe of the system for detecting the noise spectrum produced by the operation of the system, for example by the flowing fluid and by the operation of a pump and the associated engine. The noise signals of the microphone are transmitted to a microprocessor unit which controls a visual display unit so that the display unit displays the received spectrum.
Reference data relative to normal and abnormal noises spectra which may occur in the system are saved in the memory. This stored data can control the shut-off of the engine and/or trigger an alarm in case of a dangerous situation.
This document does not relate to the characterisation of the individual consumption of a plurality of devices from a signal acquired at a single point in a network.
The American patent application US 20070044572 relates to an apparatus for measuring the velocity of a fluid passing through a pipe. The apparatus comprises a spatial array of sensors comprising at least two sensors disposed at different axial locations along the pipe, wherein the sensors provide at least one signal indicative of a stochastic parameter associated with a characteristic of the fluid, wherein the characteristic includes at least one of unsteady temperature, density, consistency, transparency, conductivity, capacitance, resistivity and inductance. A signal processor is also provided, wherein the signal processor is configured to receive the at least one signal and determine the velocity of the fluid using the at least one signal.
The sensor is inserted into the pipe for controlling an industrial installation, in order to regulate the flow of a single device.